Taper cutting adjustment for lathes



April 1945. D. o. TRUBA ET AL 2,372,916

TAPER CUT TING ADJUSTMENT FOR LATHES Filed Dec. 30, 1942 3 Sheets-Sheet1 Jean 0. Tr /12w Elmer TLZZZQ? WWW April 3, 1945. D. o. TRUBA ET AL2,372,916

TAPER CUTTING ADJUSTMENT FOR LATHES Filed Dec. 50, 1942 5 Sheets-Sheet 2Inventor Jean 0. 77742740 77706? T .Lz'ZZ er mdWau e; E

April 3, 1945. D. 0. TRUBA ET AL 2,372,916

TAPER CUTTING ADJUSTMENT FOR LATHES Filed Dec. 30, 1942 v 3 Sheets-Sheet5 Inventor J Jean 0. Trzafifl fi- Elmer ZLaZZer Patented Apr. 3, 1945TAPER CUTTING STMENT'FOR LATHES Dean 0. Truba, South Gate, and Elmer T.Liller, Los Angeles, Calif.

Application December 30, 1942, Serial No. 470,618

4- Claims.

This invention relates to new anduseful improvements in taper cuttingadjustments for lathes and more particularly to an improved tail stockwhereby the tail stock end at work can be held off center and adjusted arequired toward the cutting tool.

Another important object of the invention is to provide an adjustabletail stock of the cha acter stated wherein the parts can be readilyadjusted to permit cutting of tapers of "any desired pitch-orle'ngth.

Other objects and advantages of the invention will become apparent tothe reader of the following description;

In the drawings:

Figure 1 i a fragmentary top plan view fragmentarily showingthe tailstock port on of a lathe with the present invention installed.

Figure 2 is a fragmentary front elevational view of the structure shownin Figure 1.

Figure 3 is a fragmentary side elevational view of the structure shownin Figure l.

Figure 4 is a fragmentary vertical sectional view taken substantially onthe line 4--4 of Figure 1.

Figure 5 is a fragmentary horizontal sectional view taken substantiallyon thellne 5-5 of Figure 2.

Figure 6 is a fragmentary vertical sectional view taken substantially onthe line 3-6 of Figure 3.

Referring to the drawings wherein like numerals designate like parts, itcan be seen in Figure 4 that numeral 5 denotes a lathe tail stockthrough which is disposed a lathe spindle B, the stock 5 being providedwith the usual lock lever l.

Numeral 8 denote a base plate having a tapered stub shaft 9 protrudingtherefrom and disposed into the hollow spindle 6, where a lock screw l0work into a longitudinal groove there in. The stub shaft 9 is left handthreaded into the base plate 8.

On the face side of the base plate 8 is a block H having adovetail-shaped formation l2 thereon and outwardly of this is a guideshoulder l3, over whichtrides the channeled portion M of an outer blockwhich has a dovetail-shaped grooveway l6 therein to receive thedovetailshaped formation I 2. A gib i! is interposed between one sideportion of the dovetail formation I2 and one s de wall of thedovetail-shaped groove I6, as clearly shown in Figure 4.

The block II has a longitudinally extending pocket l9 therein, one endbeing closed to form a wall through which the smooth portion 2! of ascrew shaft 22 is journaled. A hand-wheel 23 is provided at thi end ofthe shaft 22, the shaft '22 having a reduced and threaded portion 24protruding from the smooth end 2! and equipped with a nut 25 for hold ngthe knurled wheel 23 in place, with a tubular hub portion 23 thereofriding against the corresponding end of the block I l. The hub 23 and ashoulder 2! on the shaft 22 cooperate to swivelly mount the screw shaft22 and prevent longitudinal move-' ment thereof.

In the pocket I 9 is a nut 28 held in place by a set screw 29 and as isshown in Figure 5, the screw shaft 22 is disposed through thi nut 23.Small set screws 28a (see Figure 2) are employed for securing the nut28, when desired.

The remaining end of the screw shaft 22 has a reduced and threadedportion 3! on which the hub portion 3| of a second knurled hand wheel 32is feedable, the hub 31 having a flanged end portion 33 and a, tubularskirt extension 34 capable of binding in place to lock the shaft 22against rotation.

Obviously, when the, hand wheel 32 is loose, rotation of the hand wheel23 will serve to feed the nut28 and the outer block l5 by which it iscarried, and this obviously adjusts a center pin 35 to the desiredoff-centered position.

The center pin 35 comprises a ball 36 and a tapered shank extendingtherefrom, the shank portion being wedged into a tapered opening in acap structure 31 which is internally threaded for disposition over astud 38 secured to'the block I5.

A set screw 39 is feedable through one side of the cap 31 and againstthe stud 38 to lock the cap 31 against unscrewing from the stud 38, theset screw 39 being provided with a laterally disposed handle 40, whichcan be used to rotate the cap 31 in driving the pin 35 against the blockto dislodge said pin when desired;

Graduated markings 4|, 42 re provided on the blocks II and IS in orderthat micrometric adjustments can be obtained.

As is clearly shown in Figures 2 and 4, an adjustable stop member 45depends from a slot in the bottom of the block l5 and is capable ofbeing stopped against a fixed stop member 46 I projecting outwardly fromthe base plate 8.

Obviously, in the operation of this device, the hand wheel 32 can berotated so as to disengage the flange 33 from the adjacent end of theblock ll, thus freeing the shaft 32, so that it may be rotated by thehand wheel 23 in order to move the slidable-block l5, thus carrying thecenter pin 36 to the desired off-center position.

It will be apparent, that the purpose of the pin 45 and stop member 46is to stop the block IS with the pin 35 on dead-center when the block I5is moved to the left in Figure 2.

The pin 35 has a ball head which will obviously accommodate work movedtoany diverged position oil of the axis of the lathe, incontradistinction to tapered pins which would obviously causeconsiderable wear in the work.

While the foregoing specification sets forth the invention in specificterms, it is to be understood that numerous changes in the shape, sizeand materials may be resorted to without departing from the spirit andscope of the invention as claimed hereinafter.

Having described the claimed as new is:

l. A taper cutting mechanism for lathe comprising a pair of tail stockblocks, one of said blocks being fixed against transverse movement, theother block being movably mounted on the fixed block, a threaded capcarried by the movable block and having a central opening, and a taperedcenter pin positioned in the opening and movable into engagement withthe movable block to eject the pin upon a predetermined threadingmovement of the cap.

2. A taper cutting mechanism for lathe cominvention, what prising a pairof tail stock blocks, one of saidblocks being fixed against transversemovement, the other block being movably mounted on the fixed block and acenter pin on the movable block, a screw shaft for feeding the movableblock on the stationary block, said shaft provided with a threadedextension and a feedable member on the threaded extension adapted tobind against one end of the fixed block to prevent rotation of theshaft.

3. A taper cutting mechanism for lathes, comprising a pair of tail stockblocks, one of said blocks being fixed against transverse movement, theother block bein movably mounted on the fixed block, a center pin on themovable block, said fixed block being provided with a transverseaperture, a nut on said movable block extending into said aperture, ascrew shaft in said aperture engaging said nut for feeding the movableblock on the stationary block, a threaded extension on said shaft, arotatable internally threaded member on said threaded extension, and ashoulder on said member adapted to abut and bind against one end of saidfixed block to prevent rotation of said shaft.

4. A taper cutting mechanism for lathes, comprising a pair of tail stockblocks, one of said blocks being fixed against transverse movement, theother block being movably mounted on the fixed block, a center pin onthe movable block, said fixed block being provided with a transverseaperture, a nut on said movable block extending into said aperture, ascrew shaft in said aperture engaging said nut for feeding the movableblock on the stationary block, a threaded extension on said shaft, arotatable internally threaded member on said threaded extension, ashoulder on said member adapted to abut and bind against one end of saidfixed block to prevent rotation of said shaft, dead center-determiningstop abutment on the block and micrometer gauge means on said block forindicating the relative position of said movable block.

DEAN O. TRUBA. ELMER T. LILLER.

